2021 Equine Case Reports of West Nile Virus 

reported to the ArboNET reporting system as of 01/11/2022 

STATE COUNTY # EQUINE CASES 

AL Baldwin County 1 

AL Conecuh County 1 

AL Cochise County 1 

AZ Gila County 1 

AZ Graham County 3 

AZ Maricopa County 8 

AZ Pima County 8 

AZ Pinal County 2 

AR Unreported County 1 

CA Amador County 1 

CA Fresno County 2 

CA Kings County 1 

CA Merced County 1 

CA Sacramento County 2 

CA San Joaquin County 3 

CA Stanislaus County 1 

CA Yuba County 2 

CO Adams County 3 

CO Boulder County 1 

CO Douglas County 1 

CO Elbert County 1 

CO El Paso County 1 

CO Fremont County 1 

CO Larimer County 1 

CO Logan County 1 

CO Mesa County 1 

CO Morgan County 2 

CO Otero County 1 

CO Weld County 9 

DE Kent County 1 

FL Glades County 1 

FL Hendry County 1 

FL Lee County 1 

FL Suwannee County 1 

FL Volusia County 1 

IA Howard County 2 

ID Ada County 4 

ID Blaine County 1 

ID Canyon County 3 

ID Elmore County 1 
ID Gooding County 1 

ID Lemhi County 2 

ID Payette County 1 

ID Twin Falls County 1 

ID Washington County 1 

IL Douglas County 3 

IL Moultrie County 1 

IL Richland County 1 

IN Adams County 6 

IN Elkhart County 1 

IN Monroe County 1 

IN Ripley County 1 

KS Ford County 1 

KS Shawnee County 2 

KY Ballard County 1 

KY Christian County 1 

KY Graves County 1 

KY Todd County 1 

KY Trigg County 1 

KY Woodford County 1 

LA Beauregard Parish 1 

MI Genesee County 1 

MI Kent County 1 

MI Lenawee County 1 

MI Midland County 1 

MI Montcalm County 1 

MI Sanilac County 1 

MI Van Buren County 1 

MN Benton County 1 

MN Crow Wing County 1 

MN Freeborn County 1 

MN Wadena County 1 

MO Macon County 1 

MO Moniteau County 2 

MT Philips County 1 

MT Richland County 1 

NE Arthur County 1 

NE Cherry County 1 

NE Grant County 1 

NE Holt County 1 

NE Lincoln County 1 

NE Scotts Bluff County 1 

NE Sheridan County 1 

NM Dona Ana County 1 
NM Luna County 1 

NM Otero County 2 

NM Quay County 1 

NM Santa Fe County 1 

NY Cattaraugus County 1 

NY Chautauqua County 1 

NY Lewis County 1 

NY Onondaga County 1 

NY Yates County 1 

NC Guilford County 1 

NC Union County 1 

ND Barnes County 1 

ND McIntosh County 1 

ND Nelson County 1 

ND Ramsey County 1 

OH Cuyahoga County 1 

OK Coal County 1 

OK Kiowa County 1 

OK Oklahoma County 2 

OK Payne County 1 

OK Texas County 1 

OK Woodward County 1 

OR Baker County 1 

OR Jackson County 1 

OR Klamath County 1 

OR Malheur County 3 

OR Morrow County 1 

OR Umatilla County 1 

PA Cumberland County 1 

PA Lancaster County 2 

PA Northumberland County 1 

PA Snyder County 1 

SC Bamberg County 1 

SC Berkeley County 2 

SC Colleton County 1 

SC Lexington County 1 

SC Orangeburg County 1 

SC Sumter County 1 

SD Bon Homme County 2 

SD Butte County 1 

SD Jackson County 1 

SD Stanley County 1 

TN Davidson County 1 

TN Weakley County 1 
TX Freestone County 1 

TX Grayson County 1 

TX Hood County 1 

TX Llano County 1 

TX Lubbock County 2 

TX Parker County 1 

TX Reeves County 1 

TX Scurry County 1 

UT Box Elder County 2 

UT Salt Lake County 1 

UT Utah County 1 

UT Weber County 8 

WA Benton County 1 

WA Kittitas County 1 

WA Yakima County 7 

WI Crawford County 1 

WY Campbell County 1 

WY Converse County 1 

WY Platte County 1 

WY Uinta County 1 

WY Washakie County 1 

Total 220